In vivo spectroscopy: optical fiber probes for clinical applications.

INTRODUCTION: Fiber optic probe-based in vivo spectroscopy techniques are fast and highly objective methods for intraoperative diagnoses and minimally invasive surgical interventions for all procedures where endoscopic observations are carried out for cancers of different types. The Raman spectral features provide molecular fingerprint-type information and can reveal the subjects' pathological state in label-free manner, making endoscopy multiplexed fiber optic probe-based devices with the potential for translation from bench to bedside for routine applications. AREAS COVERED: This review provides a general overview of different fiber-optic probes for in vivo measurements with emphasis on Raman spectroscopy for biomedical application. Various aspects such as fiber-optic probe, radiation source, detector, and spectrometer for extracting optimum spectral features have also been discussed. EXPERT OPINION: Optical spectroscopy-based fiber probe systems with 'Chip-on-Tip' technology, combined with machine learning, can in the near future, become a complementary diagnostic tool to magnetic resonance imaging (MRI), computed tomography (CT) scan, ultrasound, etc. Hyperspectral imaging and fluorescence-based devices are in the advanced stage of technology readiness level (TRL), and with advances in lasers and miniature spectroscopy systems, probe-based Raman devices are also coming up.

A micro-Raman spectroscopy study of inflammatory condition of human cervix: Probing of tissues and blood plasma samples.

The present study explores the application of the micro-Raman spectroscopy technique to discriminate normal and cervicitis condition from cervical malignancy by analyzing the Raman signatures of tissues and plasma samples of the same subjects. The Raman peaks from tissue samples at 1026 cm-1,1298 cm-1 and 1243 cm-1 are attributed to glycogen, fatty acids and collagen and are found to be reliable signatures capable of identifying cervicitis and normal condition from cervical cancer. The Raman signatures from plasma samples belonging to carbohydrates (578 cm-1), lipids (1059 cm-1) and nucleic acids (1077 cm-1,1341 cm-1 and 1357 cm-1) are quite useful to classify various pathological conditions of cervix at par with tissue based diagnosis. The PCA-SVM based classification of the spectral data indicates the potential of Raman spectroscopy based liquid biopsy to rule out false diagnosis of cervicitis as cervical malignancy.

Blooming in the Hypothalamus.

Cavernomas are vascular malformations which are collections of endothelium-lined sinusoids without intervening cerebral parenchyma. Hypothalamic location of cavernoma is extremely rare. We present a case of a 34-year-old male who presented with complaints of recent memory loss and vomiting. On magnetic resonance imaging with gradient sequences and contrast, a diagnosis of hypothalamic cavernoma was suggested. Excision of lesion was performed by a right parasagittal pericoronal craniotomy via transcallosal approach. Intraoperative findings and histopathology examination corroborated the diagnosis. The uniqueness of this case report is in the susceptibility-weighted sequence which led to the radiological diagnosis.

Osteoporosis Prevention and Management.

Osteoporosis, defined by BMD at the hip or lumbar spine that is less than or equal to 2.5 standard deviations below the mean BMD of a young-adult reference population, is the most common bone disease in humans affecting both sexes and all races. It's a silent killer affecting the quality of life due to fractures and postural changes. In osteoporosis there is an imbalance between bone formation and bone resorption in favor of latter. Preventive measures and treatments are available to combat this evil. Counseling is the integral part of prevention as well as treatment of osteoporosis. Preventive strategy includes life style changes, exercise, intake of calcium and vitamin D, avoiding alcohol, smoking and excessive intake of salt. Estrogen therapy/estrogen+progesterone therapy (ET/EPT) is no longer recommended as a first-line therapy for the prevention of osteoporosis. They may be used in the therapy for osteoporosis in women under 60. Diagnosis and classification are made by assessment of BMD using DEXA or ultrasound and laboratory investigations. Management includes estimation of 10-year fracture risk using FRAX, life style and diet modification and pharmacological therapy. The drugs used in osteoporosis may be those that inhibit bone resorption-bisphosphonates, denosumab, calcitonin, SERMs, estrogen and progesterone-or that stimulate bone formation-PTH, Teriparatide. Combination therapies are not recommended as they do not have proven additional BMD/fracture benefits. No therapy should be indefinite in duration. There are no uniform recommendations to all patients. Duration decisions need to be individualized. While on treatment monitoring should be done with BMD assessment by DEXA/ultrasound and bone turnover markers.

Cystic Sertoli-Leydig Cell Tumour in a Postmenopausal Woman with Absent Virilising Symptoms: A Diagnostic Challenge.

A 60-year-old postmenopausal woman, presented with a left ovarian cystic mass with mildly elevated CA125 levels. An intraoperative frozen section showed oedematous ovarian stroma with interspersed large aggregates of spindle shaped stromal cells. Subsequently, the excised specimen was reported as Sertoli-Leydig Cell Tumour (SLCT) of intermediate differentiation. The leydig cells were identified in the imprint smears, but were misinterpreted as luteinized cells. The lack of tubular differentiated cells in frozen section had contributed to the misdiagnosis. Immunohistochemistry (IHC) played an important diagnostic role in the absence of clinical suspicion and lack of virilising features that are classically described in association with SLCTs. This case is unusual, as the tumour was seen in a postmenopausal woman in the absence of virilising symptoms. The cytomorphological features, IHC findings and the reasons for misdiagnosis are discussed in this case report.

Racial disparities in prostate cancer outcome among prostate-specific antigen screening eligible populations in the United States.

Background: In 2012, the United States Preventive Services Task Force (USPSTF) recommended against prostate-specific antigen (PSA) screening, despite evidence that Black men are at a higher risk of prostate cancer-specific mortality (PCSM). We evaluated whether Black men of potentially screening-eligible age (55-69 years) are at a disproportionally high risk of poor outcomes. Patients and methods: The SEER database was used to study 390 259 men diagnosed with prostate cancer in the United States between 2004 and 2011. Multivariable logistic regression modeled the association between Black race and stage of presentation, while Fine-Gray competing risks regression modeled the association between Black race and PCSM, both as a function of screening eligibility (age 55-69 years versus not). Results: Black men were more likely to present with metastatic disease (adjusted odds ratio [AOR] 1.65; 1.58-1.72; P < 0.001) and were at a higher risk of PCSM (adjusted hazard ratio [AHR] 1.36; 1.27-1.46; P < 0.001) compared to non-Black men. There were significant interactions between race and PSA-screening eligibility such that Black patients experienced more disproportionate rates of metastatic disease (AOR 1.76; 1.65-1.87 versus 1.55; 1.47-1.65; Pinteraction < 0.001) and PCSM (AHR 1.53; 1.37-1.70 versus 1.25; 1.14-1.37; Pinteraction = 0.01) in the potentially PSA-screening eligible group than in the group not eligible for screening. Conclusions: Racial disparities in prostate cancer outcome among Black men are significantly worse in PSA-screening eligible populations. These results raise the possibility that Black men could be disproportionately impacted by recommendations to end PSA screening in the United States and suggest that Black race should be included in the updated USPSTF PSA screening guidelines.

Prenatal diagnosis of congenital mesenchymal hamartoma of liver: a case report.

Hepatic mesenchymal hamartoma is a rare benign tumor. We present an unusual case of a fetal abdominal cyst, later diagnosed histopathologically to be mesenchymal hamartoma of liver. The organ of origin was indeterminate on both prenatal and postnatal ultrasounds. As there are no specific sonological findings, whenever a large multicystic fetal abdominal cyst is seen, mesenchymal hamartoma should be considered as a possibility.

Over-the-needle versus microcatheter-through-needle technique for continuous spinal anesthesia: a preliminary study.

BACKGROUND AND OBJECTIVES: A new catheter-over-needle design (Spinocath, B. Braun) has been developed to minimize problems and complications of continuous spinal anesthesia with microcatheters, which include difficult catheter insertion, failure of insertion, breakage, inadequate anesthesia, postdural puncture headache, and, rarely, development of cauda equina syndrome. METHODS: A comparative evaluation of this new catheter (22-gauge Spinocath) to the microcatheter (28-gauge Portex) was performed to study the problems of insertion, complications, quality of anesthesia, and postoperative analgesia in a prospective, randomized manner. Patients were allocated to two groups of 10 each: catheter-over-the-needle group (group I) and microcatheter-through-the needle (group II). Postoperative protocol consisted of an infusion of 0.125% isobaric bupivacaine delivered with a syringe infusion pump for 24 hours. RESULTS: The two groups were comparable in relation to age, sex, type of surgery, median height of the block, and the time taken for catheter insertion and surgery. Spontaneous backflow of cerebrospinal fluid (CSF) through the catheter with the needle in position was possible only in the spinocath group (8/10 cases). Initial introduction of the catheter into the subarachnoid space (8 vs 3: chi-square = 5.05; P = .03) and threading of the catheter were easier (8 vs 3 cases: chi-square = 5.05; P = .03) in group I. Aspiration of CSF was easy in group I in all ( 10 vs 2: chi-square = 13.33; P = .004). Complications such as resistance to drug injection, kinking (P < .05), inadequate anesthesia, and supplementation with general anesthesia were seen only in group II. Postoperative pain relief was comparable in both groups (P > .05). Both groups were comparable hemodynamically in the intra- and postoperative periods. CONCLUSIONS: Insertion, maintenance, and clinical effects were better achieved with the catheter-over-the needle design compared to the microcatheter. These preliminary findings need to be confirmed by a larger study.

Carcinoid crisis during a partial hepatic resection; lack of essential drugs: a cause for concern in the tropics.

We report a patient of carcinoid syndrome with hepatic metastasis (primary lesion in the ileum) who was posted for a right hepatic lobe resection and excision of the primary lesion. The patient developed carcinoid crisis with excessive blood loss due to vasodilation and severe hypotension during surgery. This case highlights the lack of essential drugs in the management of an intraoperative carcinoid crisis in this part of the world.

Laryngeal changes following long-term stenting with polyvinyl chloride tubes.

BACKGROUND: To treat tracheal stenosis and permit wound healing to occur an inert stent is required which resists the contraction process and prevents re-stenosis. The newer stents of polyvinyl chloride are not readily available in India and endotracheal tubes are used in many centres. In our centre polyvinyl chloride tubes are used nasotracheally for prolonged periods. We prospectively studied the pattern of laryngeal changes that occur because of prolonged nasotracheal stenting with polyvinyl chloride tubes. METHODS: The incidence and pattern of laryngeal changes due to stents was prospectively studied at the time of removal of stents, using an operating microscope. Twenty-nine patients underwent tracheal reconstructive surgery for tracheal stenosis (post-intubation or post-tracheostomy) and tracheal injuries. RESULTS: Twelve different lesions were noted and their pattern was related to the period of stenting. Fibrosis, fibrous band formation and webs were noted after four weeks. A high incidence of laryngeal changes was seen in all age groups with an overall incidence of 79% (males 79%; females 88%; adults 82%, children 75%). The mean (SD) duration of stenting was 50 (33) days. Patients with laryngeal changes had a significantly (p < 0.05) longer duration of stenting [56 (34) days] compared to those without any lesion [29 (15) days]. CONCLUSIONS: After four weeks of stenting the severity and incidence of laryngeal changes increase. We recommend restriction of the use of polyvinyl chloride stents to less than four weeks to prevent permanent laryngeal damage.

Diazepam induced delirium.

In Ophthalmic practice diazepam is often used a a premedicant. We report a case where administration of diazepam led to a state of acute delirium because of which surgery had to be postponed. The possible mechanisms for this reaction and the treatment is discussed. This side effect of diazepam should be kept in mind while dealing with delirium in the geriatric age group.